Classified communication of some LinuxUnix commands: ftp file transfer protocol login logs on to Unixmailx to read or send emails to rlogi
Summarizes the usage of some Linux/Unix commands.
Communication:
Ftp file transfer protocol
Login logs on to Unix
Mailx reads or sends emails
Rlogin logs on to remote Unix
Write talk to other terminals
Telnet to another system
Vacation automatically responds to emails
Comparison:
Cmp compares two files by byte
Comm compares entries in two sort files
Diff compares two files row by row
Diff3 compares 3 files
Dircmp comparison Directory
Sdiff compares two files side by side
File management:
~ Represents the user's home directory (yourhome directory)... represents the parent directory. represents the current directory
Cat connects to multiple files or displays them Ctrl + D. The input is as follows:Cat list1 list2> biglistWhatthis is doing is reading the contentsList1AndList2In turn, then outputing the text tothe fileBiglist
After the cd directory is changed, directly typing cd without the directory path will directly return to the user's working directory (this is very important when the user is lost in the file directory tree)
Chmod changes the file access mode
Copy a cp file, for example:CpFile1 file2Is the command which makes a copyFile1In the current working directory andcils itFile2
Csplit separates files at specific locations
File to determine the type of a file
Head: displays the lines starting with the file.
Ln creates an alias for a file
The ls list displays files or directories. when a user logs on to the system, the working directory is/home/user_name, where user_name is the user name. If you type ls separately, the preceding parameters are not included. is displayed, because. files starting with Unix are hidden and important. unless you are familiar with Unix, you are generally not advised to modify these files. Type ls-a to display all files (including files starting with.) ls-l
Create a directory using mkdir
More Display files on screen
Move or rename a file or directory
Pwd output working directory output the complete path of the current directory
Rcp copies files to a remote system
Rm delete File
Rmdir delete directory
Split splits multiple files evenly
Tail displays the last few lines of the file
Wc calculates the number of rows, words, and characters in a file.
Others:
Banner Display advertisement words
Bc calculator with arbitrary precision
Cal display calendar
Calendar detection memorandum
Clear screen
Man obtains the help information of a command.
Nice lowers the priority of a job
Nohup saves a running job after exiting the system
Passwd: set the system logon password
Script generates a copy of the login session
Spell reports misspelled words
Su becomes a super user
Print:
Cancel cancels a printer request
Lp sent to printer
Lpstat obtains the printer status
Pr format the printer content and edit the page number
Programming:
Cb C language source code optimizer
Cc C language compiler
Function flowchart of cflow C language
Ctags C language function reference (for vi)
Ctrace uses the C language debugger for function call tracking
Cross-reference of cxref C language
Lint C Language Program Analyzer
Ld loader
Lex lexical analysis generator
Make executes the command in the specified order.
Od dump input in different ways
Strip deletes data from a target file
Truss tracking signals and system calls
Yacc analysis program generator, which can be used together with the lex command
Search:
For example, enter less liao.txt and then run the command to stay in the less command. then, press enter/enter the content you want to search and Press q to exit the less command.
Extended version of the egrep grep command
Fgrep searches for files based on words
Find search system by file name
Gerp searches for files based on text format
Strings searches for binary files based on text format
Shell Programming:
Echo repeats command line parameters in input.
Expr performs arithmetic operations and comparison
Line
Printf format and print command line parameters
Sleep pause processing
Test a condition
Storage:
Compress files to free up space
Cpio copies the file to or from the disk
Gunzip uncompress (.gz and. z) files (preferred command)
Gzcat displays the content of the compressed file (which can be used with the zcat command)
Gzip compressed file to release Space (preferred command)
Tar tape archives can also uncompress. tar format files such as tar-xvf units-1.74.tar
Uncompress decompressed file (. z format)
Zcat displays compressed file content
System Status:
At then run the command
Group where the chgrp file is modified
Chown: modify the owner of a file
Crontab automatically executes the command
Date: Display or set the date
Df shows idle disk space
Du: displays disk space usage
Env display environment variables
Finger displays user information
Kill to terminate a running command
Ps display process
Set or display terminal devices
The user who displays logon appears to be able to display logon users only after entering whoami in cygwin.
Text processing:
Cut select columns to display
Ex vi line editor
Fmt makes the length of each line of text roughly the same
Join combines different rows into a database
New version of the nawk awk command (pattern matching language for text database files)
Combine columns or change the column sequence in paste.
Sed non-interactive text editor
Sort sorts or merges files. you can also sort command line input directly, for example, directly type sort. Sort List2 indicates that the content of list1 is used as the sorting input and then output to list2.
Tr conversion (redefinition) characters
Uniq searches for duplicate or unique rows in a file.
Vi visual text editor
Xargs processes multiple parameters in the manageable part
Compile the program source code to form the installation package:
The simplest way to compile a packageis:
- CdTo the directory containing the package's source code.
- Type./ConfigureTo configure the package for your system.
- TypeMakeTo compile the package.
- Optionally, typeMake checkTo run any self-tests that come with the package.
- TypeMake installTo install the programs and any data files and documentation.
Optionally, type
Make cleanTo remove the program binaries and object files from the source code directory
Variable:
Generally, variables are divided into environment variables and shell variables. environment variables are generally in upper case, and shell variables are generally in lower case.
Example: % echo $ OSTYPE will return the operating system type
More examples of environment variablesare
USER (your login name)
HOME (the path name of your home directory)
HOST (the name of the computer you are using)
ARCH (the architecture of the computers processor)
DISPLAY (the name of the computer screen to display X windows)
PRINTER (the default printer to send print jobs)
PATH (the directories the shell shoshould search to find a command)
To show all values of these variables, type
% Printenv | less: the value of all environment variables is displayed.
Shell variable:
More examples of shell variables are
Cwd (your current working directory)
Home (the path name of your home directory)
Path (the directories the shell shoshould search to find a command)
Prompt (the text string used to prompt for interactive commands shell your login shell)
To show all values of these variables, type
% Set | less